The product is a set of mutually consistent 10m and 2m integrated elevation maps (DEM) in standard ascii format.There are few missing data where there is water or at land-water interfaces. However, our map does have gaps at some inland and island sites. We have opted not to fill these because there is an ongoing project at DWR to re-analyze LiDAR returns and improve the terrestrial map. The CSTARS project at UC Davis is doing this as well.

This product is developed based on synthesizing LiDAR, single- and multibeam sonar soundings and existing integrated maps collated from multiple sources. The following figure shows the data sources used for different areas. The western part of our Bay-Delta work blends the original Foxgrover map with the 1/3 arc second DEM produced by NOAA. These are close in the region of overlap and edge-matches the NOAA data well, but the NOAA map seems to capture things like bridge footings that the original 10m Foxgrover map of the region smooths. A richer 2m product combining new data and some interpolation is due to be release by USGS in Winter or Spring 2013. Our previews of this map indicate that it is heavily based on the 1/3 arc second NOAA map for points near Carquinez Straits. For more information, please refer to the article: A Continuous Surface Elevation Map

Please note that we distribute only our own integrated maps, not the original constituent data.

* Many of the 2m DEMs are concentrated in the areas of specific channels. They are seamless maps between the water body and surrounding LiDAR beyond the levee crest. The 2m DEMs should match DWR 2007/2008 LiDAR survey (Dudas, J. 2010, LiDAR data for the Delta Area of California).